It's easy to get confused discussing things we don't clearly see. It's even easier when someone's trying to confuse us. There is one mistake I'd like to caution people to avoid.

The term 'dimension' refers to a very specific, easily identified concept, if you think about it. A dimension is simply a direction in which something may possibly move. It is nothing more, nothing less.

One may refer to alternative realms using accurate terms, as seen above. An alternative "reality" is a coherent concept; one might even call it "parallel", although that's unnecessary until some actual parallel aspect is established.

The point I would like to stress is that "parallel dimension" - a term often encountered, and often employed without thought - is incoherent and erroneous. There are exactly three dimensions, and this observation is easily confirmed by experiment. Any talk of additional dimensions is contradictory to reality, for if such dimensions existed, objects would have the capacity to move in those directions.

I certainly believe heaven exists. It makes sense that there are more realms. What I point out here is simply that referring to such realms as "dimensions" is an easily-avoided mistake.